Published online by Cambridge University Press: 31 May 2012
The effectiveness of 16 experimental compounds as soil insecticides was assessed under laboratory conditions. Chlorpyrifos, carbofuran, and dieldrin were included as standard insecticides. Spectrum of activity as contact insecticides was determined using 24–48 h nymphs of the field cricket, Acheta pennsylvanicus (Burmeister), 24–48 h onion maggot adults, Hylemya antiqua (Meigen), third stage darksided cutworms, Euxoa messoria (Harris), northern corn rootworm adults, Diabrotica longicornis (Say), and honeybees, Apis mellifera L. First stage crickets were used to assess the biological activity of experimental compounds relative to soil type, moisture, and temperature and also their volatility in moist sand and persistence of biological activity over a 48 week period. All of the insecticides showed broad spectrum contact activity. Twelve showed fair to very good potential in soil. Four insecticides, Shell WL 24794 (O,O-dimethyl-S-1-[3-(5-methyl-1,2,4-oxadiazolyl)] ethyl phosphorodithioate), Shell WL 25735 (O-[2-chloro-1-(2,5-dichlorophenyl) vinyl] O-methyl methylphosphonothioate), Shell WL 26738 (O-[1-(2,4-dichlorophenyl) vinyl] O-methyl ethylphosphonothioate), and chlorpyrifos-methyl showed good potential. Two others, Counter® (S-[(tert-butylthio) methyl] O,O-diethyl phosphorodithioate) and Shell WL 24073 (O-[2-chloro-1-(2,5-dichlorophenyl) vinyl] O-methyl ethylphosphonothioate) were considered to have very good potential as soil insecticides.